Another activity like Whowhatwherewhenwhy is Whothatwherewhenbecause. This one is oral, and focuses on clauses. One person starts a storyand stops with the word Who (There once was a princess who...) and the next student continues until That (...had a magic mirror that...) and so on. You can either stop the story after Because or keep it going until all have spoken.

Also, instead of a run-on sentence, I've had students tell the story for a certain period of time (a couple minutes), then end with Who, etc.